Question

GEO satellite transmits a signal in an 11700 MHz downlink channel. What is the path

loss the signal experiences? If the EIRP is 40 dBW, and the receiver noise level is
−125 dBm, what is the received SNR if the earth station antenna gain is 60 dB? Can this
system support high quality analogue voice communications if the required SNR is 30 dB?

Answer 1

The path loss can be calculated using the Friis transmission equation. The received SNR can be found using the EIRP, receiver noise level, and earth station antenna gain. Whether the system can support high quality analogue voice communications depends on the required SNR and the received SNR.

Step-by-step explanation:

The path loss experienced by the signal can be calculated using the Friis transmission equation:

Path Loss (dB) = 20log(d) + 20log(f) - 147.55

Where d is the distance between the satellite and the receiver (in meters) and f is the frequency of the signal (in MHz). In this case, the path loss can be calculated using the given values as:

Path Loss (dB) = 20log(100000) + 20log(11700) - 147.55

Using the EIRP, receiver noise level, and earth station antenna gain, we can find the received SNR using the formula:

Received SNR (dB) = EIRP - Path Loss - Receiver Noise Level + Earth Station Antenna Gain

Given the required SNR of 30 dB, we can compare it to the received SNR to determine if the system can support high quality analogue voice communications.